Air-cooled condensers are used with steam turbine power plants to directly condense exhaust steam flow from the steam turbine and return condensate to the power plant boiler without water loss. An air-cooled condenser unit typically comprises an A-frame or delta arrangement of exhaust steam duct distributing steam to finned tubes and down through the tubes that condense the exhaust steam. Air fans at the base of the A-frame deliver cooling air upward over the finned tubes to ambience. Condensate is drained effectively in such condensers and returned to the boiler without loss.
These condenser units are used in electrical power plants and other energy plants of all sizes, and are normally arranged in multiple rows within a surrounding wind wall.
The air-cooled condensers including exhaust steam distribution ducts and finned tubes are located outdoors open upwardly to the atmosphere, and are susceptible to hail storm damage. The size of a hailstone and its velocity determine the amount of damage caused by impact on condenser exhaust steam distribution ducts and finned tubes. The momentum of a hailstone can be calculated as equaling the mass of the stone times its velocity. If the value of either or both of these values can be reduced, the momentum of a hailstone will be less when it hits a heat transfer surface and thus less energy will be imparted to the condenser.
Finned tubes in an air cooled condenser are a point of transfer of exhaust steam heat to ambient cooling air. Hailstone damage to finned tubes can significantly reduce their heat transfer capability, and power plant capacity. Fin damage is detrimental mainly because once crushed, air flow is blocked rendering those sections of heat transfer surface basically useless. In a severe hailstorm where fins are crushed overall plant power generating capacity can be reduced by as much as 25%. Damage to the fins is permanent and the value of the power plant is degraded. At an approximate value of $2000 per KW, loss of power plant capacity is costly in degraded plant value.
The present invention provides a system to protect heat transfer surfaces of air-cooled condensers from damaging thermodynamic and economic effects of hailstone impact.